Recently, in the field of electronic devices, a mixed semiconductor device including a CMOS logic circuit of silicon (Si) and a large-capacity nonvolatile memory has become important.
A magnetoresistive random access memory (MRAM) performs nonvolatile storage of information in addition to high-speed rewriting of information with no limitation. Because of this, the MRAM has attracted attention as a new nonvolatile memory which replaces not only the memory for the use as a ROM, such as a flash memory, but also the memory for the use as a RAM, such as an SRAM and a DRAM.
Up to now, the orientation of the magnetization free layer is reversed using a magnetic field induced by causing a current to flow through a wire. However, in recent years, it has been found out that the magnetization of the magnetization free layer can be reversed by a spin-transfer torque (STT) (torque of a spin-polarized electron) (spin injection magnetization reversal). Due to this, the current used for rewriting can be reduced, and therefore, the possibility of the practical use of the MRAM is further increased.
Non-Patent Literature 1 describes a fundamental configuration of a spin injection type MRAM).
Further, Patent Literature 1 describes a semiconductor storage device in which read accuracy of data from the cell array has been improved in the MRAM.